#244366 (C#(csc)) No.117 組み合わせの数

• 問題: No.117 組み合わせの数
• ユーザー: AreTrash
• 提出日時: 2018-03-15 16:10:15
• 言語: C#(csc) (csc 3.9.0)
• 結果: AC
• 実行時間: 490 ms / 5,000 ms
• コード長: 4,828 bytes
• コンパイル時間: 1,160 ms
• コンパイル使用メモリ: 115,308 KB
• 実行使用メモリ: 41,096 KB
• 最終ジャッジ日時: 2024-12-17 17:00:50
• 合計ジャッジ時間: 2,832 ms
• ジャッジサーバーID （参考情報）: judge4 / judge5

ファイルパターン	結果
other	AC * 1

コンパイルメッセージ

Microsoft (R) Visual C# Compiler version 3.9.0-6.21124.20 (db94f4cc)
Copyright (C) Microsoft Corporation. All rights reserved.

ソースコード

using System;
using System.IO;
using System.Collections.Generic;

namespace No117_1
{
    public class Program
    {
        void Solve(StreamScanner ss, StreamWriter sw)
        {
            //---------------------------------
            var T = ss.Next(Int);
            var comb = new Combination(2000000);

            for (var i = 0; i < T; i++)
            {
                var S = ss.Next(String);
                var Q = S[0];
                var sp = Array.ConvertAll(S.Substring(1).Trim('(', ')').Split(','), int.Parse);
                var N = sp[0];
                var K = sp[1];

                if (Q == 'C') sw.WriteLine(comb.NCK(N, K));
                if (Q == 'P') sw.WriteLine(comb.NPK(N, K));
                if (Q == 'H') sw.WriteLine(comb.NHK(N, K));
            }
            //---------------------------------
        }

        static void Main()
        {
            var ss = new StreamScanner(new StreamReader(Console.OpenStandardInput()));
            var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
            new Program().Solve(ss, sw);
            sw.Flush();
        }

        static readonly Func<string, string> String = s => s;
        static readonly Func<string, int> Int = int.Parse;
        static readonly Func<string, long> Long = long.Parse;
        static readonly Func<string, double> Double = double.Parse;
    }

    public struct ModInt
    {
        public static int Mod = 1000000007;

        readonly long value;
        public int Value { get { return (int)value; } }
        public ModInt Inverse { get { return GetInverse(); } }

        public ModInt(long value)
        {
            value %= Mod;
            this.value = value < 0 ? value + Mod : value;
        }

        ModInt GetInverse()
        {
            if (value == 0) throw new InvalidOperationException("value must NOT equal 0");
            return Pow(Mod - 2);
        }

        public ModInt Square()
        {
            return this * this;
        }

        public ModInt Pow(long exp)
        {
            if (exp == 0) return 1;
            if (exp % 2 == 0) return Pow(exp / 2).Square();
            return this * Pow(exp - 1);
        }

        public static ModInt Parse(string str)
        {
            return long.Parse(str);
        }

        public static implicit operator ModInt(long value)
        {
            return new ModInt(value);
        }

        public static ModInt operator +(ModInt left, ModInt right)
        {
            return left.value + right.value;
        }

        public static ModInt operator -(ModInt left, ModInt right)
        {
            return left.value - right.value;
        }

        public static ModInt operator *(ModInt left, ModInt right)
        {
            return left.value * right.value;
        }

        public static ModInt operator /(ModInt left, ModInt right)
        {
            return left * right.Inverse;
        }

        public override bool Equals(object obj)
        {
            if (!(obj is ModInt)) return false;
            return value == ((ModInt)obj).value;
        }

        public override int GetHashCode()
        {
            return value.GetHashCode();
        }

        public override string ToString()
        {
            return value.ToString();
        }
    }

    public class Combination
    {
        readonly ModInt[] facts;

        public Combination(int max)
        {
            facts = new ModInt[max + 1];
            facts[0] = 1;
            for (var i = 1; i <= max; i++) facts[i] = facts[i - 1] * i;
        }

        public ModInt Fact(int n)
        {
            return facts[n];
        }

        public ModInt NCK(int n, int k)
        {
            if (n < k) return 0;
            return facts[n] / facts[k] / facts[n - k];
        }

        public ModInt NPK(int n, int k)
        {
            if (n < k) return 0;
            return facts[n] / facts[n - k];
        }

        public ModInt NHK(int n, int k)
        {
            if (k == 0) return 1;
            if (n == 0) return 0;
            return facts[n + k - 1] / facts[k] / facts[n - 1];
        }
    }

    public class StreamScanner
    {
        static readonly char[] Sep = {' '};
        readonly Queue<string> buffer = new Queue<string>();
        readonly TextReader textReader;

        public StreamScanner(TextReader textReader)
        {
            this.textReader = textReader;
        }

        public T Next<T>(Func<string, T> parser)
        {
            if (buffer.Count != 0) return parser(buffer.Dequeue());
            var nextStrings = textReader.ReadLine().Split(Sep, StringSplitOptions.RemoveEmptyEntries);
            foreach (var nextString in nextStrings) buffer.Enqueue(nextString);
            return Next(parser);
        }
    }
}